基于碗扣节点力学性能的钢管支架稳定性分析

发布时间：2018-06-13 15:12

本文选题：碗扣式模板支撑架 + 半刚性　；参考：《长安大学》2016年硕士论文

【摘要】：随着我国土木工程行业的高速发展,碗扣式模板支撑架以其构造合理、制作简单、操作灵活、承载能力高、适应性强等优点被广泛应用于一些桥梁、高层建筑等混凝土结构施工过程中。但是,由于人们对该体系的认识不足,研究不到位及搭设的技术等各方面原因,导致碗扣式模板支撑架的失稳倒塌事故经常发生。因此,对碗扣式模板支撑架体系的稳定性进行深入研究,提高结构的整体稳定承载能力,避免该类失稳倒塌事故的发生尤为重要。首先,本文简单介绍了碗扣式模板支撑架现有的主要计算理论及有限元屈曲分析的理论基础,并基于碗扣节点的力学性能研究,借助有限元分析软件ANSYS中的弹簧单元等效模拟碗扣节点的半刚性,以此建立碗扣式模板支撑架的整体架体模型。其次,文章对不同连接方式下的碗扣式模板支撑架整体失稳情况进行了分析,并分析了结构失稳时刻碗扣节点的受力状态,得出了半刚性连接下的架体模型稳定承载力与实际更相符合,结构稳定承载力随碗扣拧紧力矩的增加而增加,并且模板支撑架整体往往先于碗扣节点而破坏的结论。再次,结合实际施工过程中可能出现的状况,文章分别对半刚性连接下有无方木的碗扣式模板支撑架的局部失稳进行了对比分析,得出半刚性连接下有方木模板支撑架的局部失稳对各立杆的失稳顺序有较大改变,局部失稳将会降低结构的整体稳定承载力,纵向及横向方木会增加结构稳定承载力的结论。然后,文章完成了对影响架体稳定性的因素分析,提出了碗扣式模板支撑架优化搭设的建议。最后,以某等截面连续梁桥支架为依托工程,分别对该桥支架的整体稳定性及混凝土箱梁浇筑过程中不均匀受力和不均匀沉降时的稳定承载力进行了分析,并对比规范计算结果,得出碗扣节点视为半刚性模拟更符合实际,混凝土先跨中后两端浇筑时架体稳定承载力较大,立杆不均匀沉降会降低支架稳定承载力的结论。
[Abstract]:With the rapid development of the civil engineering industry in China, the bowl-button formwork support frame has been widely used in some bridges with its advantages of reasonable structure, simple manufacture, flexible operation, high carrying capacity and strong adaptability. High-rise building and other concrete structures during the construction process. However, due to the lack of understanding of the system, the lack of research and erection of the technology and other reasons, resulting in the bowl buckle formwork support unstable collapse accidents often occur. Therefore, it is very important to study the stability of bowl-buttoned formwork bracing system, to improve the overall stability bearing capacity of the structure and to avoid this kind of unstable collapse accident. First of all, this paper briefly introduces the main calculation theory and the theoretical basis of finite element buckling analysis of the bowl-button formwork support frame, and studies the mechanical properties of the bowl buckle joint. With the help of the finite element analysis software ANSYS, the spring element is used to simulate the semi-rigidity of the bowl-buckle node, and the integral frame model of the bowl-button-type formwork support frame is established. Secondly, the paper analyzes the overall instability of the bowl button-type formwork support frame under different connection modes, and analyzes the stress state of the bowl buckle joint when the structure is unstable. It is concluded that the stability bearing capacity of the frame model under semi-rigid connection is more consistent with the actual situation, and the stability bearing capacity of the structure increases with the increase of the tightening torque of the bowl, and the whole formwork support frame is often destroyed before the bowl buckle joint. Thirdly, combined with the possible situation in the actual construction process, the paper compares and analyzes the local instability of the bowl button-type formwork support frame with or without square wood under semi-rigid connection. It is concluded that the local instability of square wood formwork braces with semi-rigid connections will greatly change the instability sequence of each stand, and the local instability will reduce the overall stability bearing capacity of the structure, while the longitudinal and lateral square timber will increase the stability bearing capacity of the structure. Then, the factors influencing the stability of the frame are analyzed, and the suggestions for optimization of the supporting frame are put forward. Finally, based on the support of a continuous beam bridge with equal section, the overall stability of the support and the stable bearing capacity of the concrete box girder during the pouring process are analyzed respectively. Compared with the calculated results of the code, it is concluded that the bowl fastening joint is more practical as semi-rigid simulation, and the stable bearing capacity of the frame is larger when the concrete is first spanned and then poured at both ends, and the uneven settlement of the shaft will reduce the stability bearing capacity of the support.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U445.3

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